Add "Who can reply" controls [WIP] (#1954)

* Add threadgating

* UI improvements

* More ui work

* Remove comment

* Tweak colors

* Add missing keys

* Tweak sizing

* Only show composer option on non-reply

* Flex wrap fix

* Move the threadgate control to the top of the composer

src/view/com/post-thread/PostThread.tsx

@@ -468,7 +468,7 @@ function* flattenThreadSkeleton(
       yield PARENT_SPINNER
     }
     yield node
-    if (node.ctx.isHighlightedPost) {
+    if (node.ctx.isHighlightedPost && !node.post.viewer?.replyDisabled) {
       yield REPLY_PROMPT
     }
     if (node.replies?.length) {